The market is there to make money
And this is the reason the market isn't the way to do health insurance:
insurers profit not by providing the most cost-effective care, but by trying to insure people who won’t need care.Krugman slapping at Wyden by channeling Ken Arrow from 50 years ago.
Insurance companies aren't intrinsically evil. But they're in it to make money. And they make money by not paying claims.
It really is that simple.